Forecasting: Just Half the Battle

Forecasting: Just Half the Battle

A TV meteorologist can make a perfect prediction, but yet, on days like yesterday, the public can be outraged by what they perceive as a “busted forecast.”

How can that be?

Whenever there are sharp temperature gradients, simple generic forecasts for the public cannot resolve the small scale (approx 10 km) variability. As expected, yesterday’s sea breeze resulted in cool spring-like conditions with Boston in the lower 50s°F. However, 10 km away from the coast, it was significantly warmer, with temperatures 70°F.

So how should the meteorologist communicate this forecast to the reader? They cannot just pick one side and communicate that forecast, since roughly half live on either side of the coastal front. The best way is to describe where the coastal front lies as a function of space and time. However, communicating this adds a new dimension to the forecast. So it’s not only up to the meteorologist to convey this large spatial variability in the temperature, but it’s also up to the readers to be aware of the complexity on certain days.

Nothing is complicated about today’s forecast. With sufficiently strong southwesterly winds, a sea-breeze will not form. Expect high temperatures to break the record of 90°F. However, this summer air will be short-lived, as a cold front arrives tomorrow night, leaving behind more seasonable temperatures for the rest of the week.